Whirlpools used in brewing operations are known in the art, see Ludwig Narziβ “Abriss der Bierbrauerei <Outline of Beer Brewing>”, 5th edition, Ferdinand Enkel Verlag, Stuttgart, 1986, page 319). During the preparation of the wort in beer brewing, aroma substances arise that can give the beer an unwanted smell or taste. One example of such an unwanted substance is dimethyl sulphide, which arises during the heating or boiling from an inactive precursor substance that is contained in malt. Dimethyl sulphide, also referred to as DMS in the following, itself is only present in the malt in small quantities. During the boiling process in the wort copper, the inactive precursor is cleaved into DMS and an active precursor. During the boiling process in the wort copper or the heating process in the mashing containers, the DMS is only partially distilled off. The active precursor is metabolised by the yeast that is present and converted into DMS. After the boiling process in the wort copper, there is consequently still DMS present in the wort. The boiled wort furthermore still contains other unwanted volatile substances, base aromatic substances, such as carbonyl, compounds containing sulphur, and the like.
Following the wort copper is, as previously explained, the whirlpool, for separating the hot break. The wort is kept hot in the whirlpool. Unwanted volatile substances develop here. In the finished beer, these substances lead to unwanted aromas and impair the stability of the taste. DMS, for example, in turn arises from the inactive precursor substance during the whirlpool's action period.
In order also to remove the remaining unwanted volatile substances from the wont, a so-called “wort-stripping” process has already been suggested (D. Seldeslachts et al., BrewingScience—Monatsschrift für Brauwissenschaft <Monthly Publication on the Science of Brewing>, issue 3/4, 1997, page 76 and PCT WO 97/15654). In such a wort-stripping process, the wort is directed through a wont-stripping column with an open packing. Steam takes away a part of the unwanted volatile substances, drawing them off through an exhaust gas line.
The construction and cleaning of such a device is complicated and costly, however.
In the German utility model no. 29713679.8, it has already been suggested that these unwanted volatile substances be driven out with the help of a device having at least one baffle shield that divents the wort that is being transferred. Such a device is also complicated and costly.